#include "stmflash.h"
#include "delay.h"
#include "usart.h"

////要写入到STM32 FLASH的字符串数组
//float UltraSoundHeight[4]={0.0f,0.0f,0.0f,0.0f};
//const u8 TEXT_Buffer[]={"STM32F103 FLASH"};
//#define SIZE sizeof(TEXT_Buffer)      //数组长度
//#define FLASH_SAVE_ADDR  0X08070000   //设置FLASH 保存地址(必须为偶数，且其值要大于本代码所占用FLASH的大小+0X08000000)


//读取指定地址的半字(16位数据)
//faddr:读地址(此地址必须为2的倍数!!)
//返回值:对应数据.
u16 STMFLASH_ReadHalfWord(u32 faddr)
{
    return *(vu16 *)faddr;
}
#if STM32_FLASH_WREN //如果使能了写
//不检查的写入
//WriteAddr:起始地址
//pBuffer:数据指针
//NumToWrite:半字(16位)数
void STMFLASH_Write_NoCheck(u32 WriteAddr, u16 *pBuffer, u16 NumToWrite)
{
    u16 i;
    for (i = 0; i < NumToWrite; i++)
    {
        FLASH_ProgramHalfWord(WriteAddr, pBuffer[i]);
        WriteAddr += 2; //地址增加2.
    }
}
//从指定地址开始写入指定长度的数据
//WriteAddr:起始地址(此地址必须为2的倍数!!)
//pBuffer:数据指针
//NumToWrite:半字(16位)数(就是要写入的16位数据的个数.)
#if STM32_FLASH_SIZE < 256
#define STM_SECTOR_SIZE 1024 //字节
#else
#define STM_SECTOR_SIZE 2048
#endif
u16 STMFLASH_BUF[STM_SECTOR_SIZE / 2]; //最多是2K字节
void STMFLASH_Write(u32 WriteAddr, u16 *pBuffer, u16 NumToWrite)
{
    u32 secpos;    //扇区地址
    u16 secoff;    //扇区内偏移地址(16位字计算)
    u16 secremain; //扇区内剩余地址(16位字计算)
    u16 i;
    u32 offaddr; //去掉0X08000000后的地址
    if (WriteAddr < STM32_FLASH_BASE || (WriteAddr >= (STM32_FLASH_BASE + 1024 * STM32_FLASH_SIZE)))
        return;                               //非法地址
    FLASH_Unlock();                           //解锁
    offaddr = WriteAddr - STM32_FLASH_BASE;   //实际偏移地址.
    secpos = offaddr / STM_SECTOR_SIZE;       //扇区地址  0~127 for STM32F103RBT6
    secoff = (offaddr % STM_SECTOR_SIZE) / 2; //在扇区内的偏移(2个字节为基本单位.)
    secremain = STM_SECTOR_SIZE / 2 - secoff; //扇区剩余空间大小
    if (NumToWrite <= secremain)
        secremain = NumToWrite; //不大于该扇区范围
    while (1)
    {
        STMFLASH_Read(secpos * STM_SECTOR_SIZE + STM32_FLASH_BASE, STMFLASH_BUF, STM_SECTOR_SIZE / 2); //读出整个扇区的内容
        for (i = 0; i < secremain; i++)                                                                //校验数据
        {
            if (STMFLASH_BUF[secoff + i] != 0XFFFF)
                break; //需要擦除
        }
        if (i < secremain) //需要擦除
        {
            FLASH_ErasePage(secpos * STM_SECTOR_SIZE + STM32_FLASH_BASE); //擦除这个扇区
            for (i = 0; i < secremain; i++)                               //复制
            {
                STMFLASH_BUF[i + secoff] = pBuffer[i];
            }
            STMFLASH_Write_NoCheck(secpos * STM_SECTOR_SIZE + STM32_FLASH_BASE, STMFLASH_BUF, STM_SECTOR_SIZE / 2); //写入整个扇区
        }
        else
            STMFLASH_Write_NoCheck(WriteAddr, pBuffer, secremain); //写已经擦除了的,直接写入扇区剩余区间.
        if (NumToWrite == secremain)
            break; //写入结束了
        else       //写入未结束
        {
            secpos++;                //扇区地址增1
            secoff = 0;              //偏移位置为0
            pBuffer += secremain;    //指针偏移
            WriteAddr += secremain;  //写地址偏移
            NumToWrite -= secremain; //字节(16位)数递减
            if (NumToWrite > (STM_SECTOR_SIZE / 2))
                secremain = STM_SECTOR_SIZE / 2; //下一个扇区还是写不完
            else
                secremain = NumToWrite; //下一个扇区可以写完了
        }
    };
    FLASH_Lock(); //上锁
}
#endif

//从指定地址开始读出指定长度的数据
//ReadAddr:起始地址
//pBuffer:数据指针
//NumToWrite:半字(16位)数
void STMFLASH_Read(u32 ReadAddr, u16 *pBuffer, u16 NumToRead)
{
    u16 i;
    for (i = 0; i < NumToRead; i++)
    {
        pBuffer[i] = STMFLASH_ReadHalfWord(ReadAddr); //读取2个字节.
        ReadAddr += 2;                                //偏移2个字节.
    }
}


//WriteAddr:起始地址
//WriteData:要写入的数据
void Test_Write(u32 WriteAddr, u16 WriteData)
{
    STMFLASH_Write(WriteAddr, &WriteData, 1); //写入一个字
}
